This just adds support for reporting illuminance with default settings. All default registers are written on probe because the device otherwise lacks a reset function. Signed-off-by: Crestez Dan Leonard <leonard.crestez@xxxxxxxxx> --- drivers/iio/light/Kconfig | 11 ++ drivers/iio/light/Makefile | 1 + drivers/iio/light/max44000.c | 295 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 307 insertions(+) create mode 100644 drivers/iio/light/max44000.c diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig index cfd3df8..42c15c1 100644 --- a/drivers/iio/light/Kconfig +++ b/drivers/iio/light/Kconfig @@ -320,4 +320,15 @@ config VCNL4000 To compile this driver as a module, choose M here: the module will be called vcnl4000. +config MAX44000 + tristate "MAX44000 Ambient and Infrared Proximity Sensor" + depends on I2C + select REGMAP_I2C + help + Say Y here if you want to build support for Maxim Integrated's + MAX44000 ambient and infrared proximity sensor device. + + To compile this driver as a module, choose M here: + the module will be called max44000. + endmenu diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile index b2c3105..14b2f36 100644 --- a/drivers/iio/light/Makefile +++ b/drivers/iio/light/Makefile @@ -30,3 +30,4 @@ obj-$(CONFIG_TCS3472) += tcs3472.o obj-$(CONFIG_TSL4531) += tsl4531.o obj-$(CONFIG_US5182D) += us5182d.o obj-$(CONFIG_VCNL4000) += vcnl4000.o +obj-$(CONFIG_MAX44000) += max44000.o diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c new file mode 100644 index 0000000..7c12153 --- /dev/null +++ b/drivers/iio/light/max44000.c @@ -0,0 +1,295 @@ +/* + * MAX44000 Ambient and Infrared Proximity Sensor + * + * Copyright (c) 2016, Intel Corporation. + * + * This file is subject to the terms and conditions of version 2 of + * the GNU General Public License. See the file COPYING in the main + * directory of this archive for more details. + * + * Data sheet: https://datasheets.maximintegrated.com/en/ds/MAX44000.pdf + * + * 7-bit I2C slave address 0x4a + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/i2c.h> +#include <linux/regmap.h> +#include <linux/util_macros.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/acpi.h> + +#define MAX44000_DRV_NAME "max44000" + +/* Registers in datasheet order */ +#define MAX44000_REG_STATUS 0x00 +#define MAX44000_REG_CFG_MAIN 0x01 +#define MAX44000_REG_CFG_RX 0x02 +#define MAX44000_REG_CFG_TX 0x03 +#define MAX44000_REG_ALS_DATA_HI 0x04 +#define MAX44000_REG_ALS_DATA_LO 0x05 +#define MAX44000_REG_PRX_DATA 0x16 +#define MAX44000_REG_ALS_UPTHR_HI 0x06 +#define MAX44000_REG_ALS_UPTHR_LO 0x07 +#define MAX44000_REG_ALS_LOTHR_HI 0x08 +#define MAX44000_REG_ALS_LOTHR_LO 0x09 +#define MAX44000_REG_PST 0x0a +#define MAX44000_REG_PRX_IND 0x0b +#define MAX44000_REG_PRX_THR 0x0c +#define MAX44000_REG_TRIM_GAIN_GREEN 0x0f +#define MAX44000_REG_TRIM_GAIN_IR 0x10 + +#define MAX44000_ALSDATA_OVERFLOW 0x4000 + +#define MAX44000_REGMASK_READABLE 0x419fff +#define MAX44000_REGMASK_WRITEABLE 0x019fce +#define MAX44000_REGMASK_VOLATILE 0x400031 + +struct max44000_data { + struct mutex lock; + struct i2c_client *client; + struct regmap *regmap; +}; + +/* Default scale is set to the minimum of 0.03125 or 1 / (1 << 5) lux */ +#define MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2 5 + +static const struct iio_chan_spec max44000_channels[] = { + { + .type = IIO_LIGHT, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), + }, +}; + +static inline int max44000_read_alsval(struct max44000_data *data) +{ + u16 regval; + int ret; + + regval = 0; + ret = regmap_bulk_read(data->regmap, MAX44000_REG_ALS_DATA_HI, ®val, 2); + if (ret < 0) + return ret; + + regval = be16_to_cpu(regval); + + /* Overflow is explained on datasheet page 17. + * + * It's a warning that either the G or IR channel has become saturated + * and that the value in the register is likely incorrect. + * + * The recommendation is to change the scale (ALSPGA). + * The driver just returns the max representable value. + */ + if (regval & MAX44000_ALSDATA_OVERFLOW) + return 0x3FFF; + + return regval; +} + +static int max44000_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct max44000_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + switch (chan->type) { + case IIO_LIGHT: + mutex_lock(&data->lock); + ret = max44000_read_alsval(data); + mutex_unlock(&data->lock); + if (ret < 0) + return ret; + *val = ret; + return IIO_VAL_INT; + + default: + return -EINVAL; + } + + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_LIGHT: + *val = 1; + *val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2; + return IIO_VAL_FRACTIONAL_LOG2; + + default: + return -EINVAL; + } + + default: + return -EINVAL; + } +} + +static const struct iio_info max44000_info = { + .driver_module = THIS_MODULE, + .read_raw = max44000_read_raw, +}; + +static bool max44000_readable_reg(struct device *dev, unsigned int reg) +{ + return (1 << reg) & MAX44000_REGMASK_READABLE; +} + +static bool max44000_writeable_reg(struct device *dev, unsigned int reg) +{ + return (1 << reg) & MAX44000_REGMASK_WRITEABLE; +} + +static bool max44000_volatile_reg(struct device *dev, unsigned int reg) +{ + return (1 << reg) & MAX44000_REGMASK_VOLATILE; +} + +static bool max44000_precious_reg(struct device *dev, unsigned int reg) +{ + return reg == MAX44000_REG_STATUS; +} + +/* Datasheet pages 9-10: */ +static const struct reg_default max44000_reg_defaults[] = { + { MAX44000_REG_CFG_MAIN, 0x24 }, + /* Upper 4 bits are not documented but start as 1 on powerup + * Setting them to 0 causes proximity to misbehave so set them to 1 + */ + { MAX44000_REG_CFG_RX, 0xf0 }, + { MAX44000_REG_CFG_TX, 0x00 }, + { MAX44000_REG_ALS_UPTHR_HI, 0x00 }, + { MAX44000_REG_ALS_UPTHR_LO, 0x00 }, + { MAX44000_REG_ALS_LOTHR_HI, 0x00 }, + { MAX44000_REG_ALS_LOTHR_LO, 0x00 }, + { MAX44000_REG_PST, 0x00 }, + { MAX44000_REG_PRX_IND, 0x00 }, + { MAX44000_REG_PRX_THR, 0x00 }, + { MAX44000_REG_TRIM_GAIN_GREEN, 0x80 }, + { MAX44000_REG_TRIM_GAIN_IR, 0x80 }, +}; + +static const struct regmap_config max44000_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + + .max_register = MAX44000_REG_PRX_DATA, + .readable_reg = max44000_readable_reg, + .writeable_reg = max44000_writeable_reg, + .volatile_reg = max44000_volatile_reg, + .precious_reg = max44000_precious_reg, + + .use_single_rw = 1, + .cache_type = REGCACHE_FLAT, + + .reg_defaults = max44000_reg_defaults, + .num_reg_defaults = ARRAY_SIZE(max44000_reg_defaults), +}; + +static int max44000_force_write_defaults(struct max44000_data *data) +{ + int i, ret; + + for (i = 0; i < ARRAY_SIZE(max44000_reg_defaults); ++i) { + ret = regmap_write(data->regmap, + max44000_reg_defaults[i].reg, + max44000_reg_defaults[i].def); + if (ret) + return ret; + } + return 0; +} + +static int max44000_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct max44000_data *data; + struct iio_dev *indio_dev; + int ret, reg; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + data = iio_priv(indio_dev); + data->regmap = devm_regmap_init_i2c(client, &max44000_regmap_config); + if (IS_ERR(data->regmap)) { + dev_err(&client->dev, "regmap_init failed!\n"); + return PTR_ERR(data->regmap); + } + + i2c_set_clientdata(client, indio_dev); + data->client = client; + mutex_init(&data->lock); + indio_dev->dev.parent = &client->dev; + indio_dev->info = &max44000_info; + indio_dev->name = MAX44000_DRV_NAME; + indio_dev->channels = max44000_channels; + indio_dev->num_channels = ARRAY_SIZE(max44000_channels); + + /* Read status at least once to clear the power-on-reset bit. */ + ret = regmap_read(data->regmap, MAX44000_REG_STATUS, ®); + if (ret < 0) { + dev_err(&data->client->dev, "failed to read init status: %d\n", ret); + return ret; + } + + /* The device has no reset command, write defaults explicitly. */ + ret = max44000_force_write_defaults(data); + if (ret < 0) { + dev_err(&data->client->dev, "failed to write defaults: %d\n", ret); + return ret; + } + + return iio_device_register(indio_dev); +} + +static int max44000_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + + iio_device_unregister(indio_dev); + return 0; +} + +static const struct i2c_device_id max44000_id[] = { + {"max44000", 0}, + { } +}; +MODULE_DEVICE_TABLE(i2c, max44000_id); + +#ifdef CONFIG_OF +static const struct of_device_id max44000_of_match[] = { + { .compatible = "maxim,max44000" }, + { } +}; +MODULE_DEVICE_TABLE(of, max44000_of_match); +#endif + +#ifdef CONFIG_ACPI +static const struct acpi_device_id max44000_acpi_match[] = { + {"MAX44000", 0}, + { } +}; +MODULE_DEVICE_TABLE(acpi, max44000_acpi_match); +#endif + +static struct i2c_driver max44000_driver = { + .driver = { + .name = MAX44000_DRV_NAME, + .of_match_table = of_match_ptr(max44000_of_match), + .acpi_match_table = ACPI_PTR(max44000_acpi_match), + }, + .probe = max44000_probe, + .remove = max44000_remove, + .id_table = max44000_id, +}; + +module_i2c_driver(max44000_driver); + +MODULE_AUTHOR("Crestez Dan Leonard <leonard.crestez@xxxxxxxxx>"); +MODULE_DESCRIPTION("MAX44000 Ambient and Infrared Proximity Sensor"); +MODULE_LICENSE("GPL v2"); -- 2.8.0.rc3 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
